


pretty like a rose, sharp like a thorn

by goodnight_Sord



Category: Undertale
Genre: Character/Reader - Freeform, Other, Yandere Sans, but still, if this is bad please tell me lmao, oh god i wrote this at like 7 am, they/them pronouns for reader, what am I even doing
Language: English
Status: Completed
Published: 2016-08-06
Updated: 2016-08-06
Packaged: 2018-07-29 18:04:32
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,166
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/7694170
Author URL: https://archiveofourown.org/users/goodnight_Sord/pseuds/goodnight_Sord
Summary: <blockquote class="userstuff">
              <p>AU where Sans is a yandere, because that's necessary.<br/>The skeleton's growing affections for you were poisonous- toxic- and he loved it so much. You were dangerous for his health, but he didn't care. He loved you. He'd do anything to keep you there.</p><p>That's what love is, right?<br/>[ reader / yandere!sans fanfic ]</p>
            </blockquote>





	pretty like a rose, sharp like a thorn

With an affectionate sigh, the small, chalky white skeleton was laced in his thoughts; tangled hopelessly like a fly in a spiders web. He was daydreaming of them, the one that had captured his soul.  
His head resting in his palm, his flickering pupils looked down at the wooden counter of sorts in front of him. A human had fell recently, but they were different.

They had reset several times by now yes, but.. it wasn't fustrating anymore. Getting to see the surface again- but ripping it just out of his phalanges. No, he didn't mind anymore, as long as you were there.  
You. The human that had captured his soul like a photo would capture memories,  
were just a mere human. Nothing out of the ordinary.

Even then, it spiked dangerous feelings in the skeleton. Similar to a rose, it was beautiful and blossomed wonderfully- but had thorns and chased away outsiders, wary of those who attempted to pluck it from its green home.  
He wanted them all for his own, almost able to feel their rose in his hands, its delicate petals dancing along his fingertips and making him flourish. A blue blush settled upon his cheekbones at the thought of you and it was driving him insane.

Not that it hadn't already, to an extent. He was willing to do anything for this simple human, whether it was dangerous or no. But he wasn't going to just be an open book out of desperation to get them in his arms, that would be silly.  
He'd wipe out the competition, of course. Whether it be domestic or not-so, he'd find a way to have you be his one and only. Not even Doggo would be able to get close, he'd forbid it.  
Eventually, it would be reminiscent of a web. You'd be stuck with him, its silvery unforgiving strands glistening with little beads of water- and the spider would tend to it oh so caringly, keeping it prepared for any disasters.

Was that controlling? Yeah, that sounded controlling.. He couldn't be controlling around you, he loved you. Being controlling was bad in a relationship, that would only instinctively raise thorns from that soft rose he wanted to touch and hold close, but that isn't to say he'd control you like a puppet when it mattered. He'd dance you on all the right strings- he was sure of it, with all his constant observations of what tethered you along or made you shove it away.

Fragile. Oh so fragile. If he made one wrong move, the rose would turn him away. But if he managed to play his cards right, it would let him in. He wanted to be that one who could truly break down your walls and love you- but he wanted to be the only one, until you died even.

He was willing to stay that long. Because he loved and obsessed over you, and that was what love was. At least, he assumed it was, because it had to be true. He was lovesick for every little detail and curve you had on your body.

Toxic buds formed on his soul, and it was anything but your fault. It was his fault for letting it get this far. It was nobody's fault, actually. He just wanted you too much and thats all he cared about, his feelings that had originally just simmered now having come to an overwhelming boil.

Soon it would boil over, but it wouldn't return to that gentle, calming heat that would hurt a little, but wouldn't burn. It would stay in a volcano of a boil, threatening to singe all of those who tried to stop it.  
He'd repeat the words you said in his head every now and then, as he thought of you like a novel. Every little thing you spoke of and every appearence you had was worth a million more in his eyesockets.  
That was similar to what came to his mind every single time he thought of you. It hurt him sometimes to know that he'd have to do some dirty work- but you would never love him under any other circumstances. Right? Right. That's what he'd keep telling himself.

A sharp thud was enough to yank him out of his flower scented daydreams, their bliss left interrupted.  
"Hey!" The captain was loud to further rip him away from what made him happy, her hands placed firmly on the wood before him. He gave her a lazy gaze, smile forced and fake. God, how he hated Undyne.  
Wait, since when did he hate her? He forgot and didn't care anymore.

His usual sonorous voice was returned in a resounding grumble of his own, bemused but not quite amused. "what do you need, fish flakes?" He asked. His little nickname for her was indeed recent. Not because of you, of course..  
.. or was it? He didn't pay much attention to any influence you had over him, other then his interest in you. He was always a little unintentionally rude to Undyne after she'd tried to murder you this run. He couldn't do anything of course, but it was slight retaliation, unknowing, but still.

"Paps has been calling you for three fucking hours. Do you have your phone on silent? I had to run over here cause we were cooking." She snarled, fins aggressively raising.  
"yes." He answered blankly. "i forgot to turn the sound back on. was nappin'." She didn't need to know. He was away from shift and watching you- which wasn't creepy at all.  
Totally not creepy. Yes Sans, you are completely right.

No matter how many times he told himself that, he wasn't convinced. It honestly sounded like he was a stalker- which he would deny, of course, but.. Watching you from afar.. staring..  
.. What was going on again?

Shit. The tall, scaled woman was waiting for an answer and waved a hand in his face. "Sans! Don't blank out on me, god dammit.."  
"s-sorry." He stuttered. "haven't had time to sleep lately cause i forgot about pap's storytime once or twice. i'm a real bag of bones when it comes to that, heh.." Sans managed to dryly chuckle. It felt strange faking a laugh about this.

In truth, he lied about the reason. He had a hard time getting a good nights rest when all he could think of was- you guessed it- you.  
The female sighed, her red flowing ponytail making the situation slightly worse. It was easier to just watch it and fall asleep, gently waving at him like a scarlet, welcoming flag, but he needed to put up with Undyne. Geez, it was so easy to get distracted when it wasn't you that mattered right now, as obvious as it was.

"We're actually getting kinda worried, punk. Pap says you've been more distant then ever since the human fell."  
The blue-clad skeleton shrugged, the white pinpricks of light in his dark eyesockets giving off a gentle light and observing his fishy friend's face, seeming almost unfocused. "i've just been real busy doing m'job for once."

yeah. sure, sans. "job." He remarked at himself mentally, but his expression didn't dare shift. The fishmonster didn't seem to buy it, but sighed, and offered him a big toothy grin, yellow fangs glistening slightly.  
"Alright, fine." She gave in, turning to leave. Before everything was said and done, one more thing was spoken. "Sans, you gotta keep work and Pap balanced, y'know?.. Anyway. The human'll pass by here soon. Keep watch on em', you don't want them getting hurt. Pap would kill me- and I'd kill you."

Of course she was joking. Why she annoyed him so much, even with jokes as of late was both obvious and not-so obvious to the smaller. This had only become a recent thing as well, but oh well.  
Something else mattered- they'll be near him again.  
That made his soul flutter. they'll be here soon. I can't fuck this up. please don't fuck this up. His lack of a heart was going to beat right out of his chest at this point, and he felt anxious. 

"right. how long do you think it'll take?" Did he hide the desperation in his voice? God, he hoped so.  
"Maybe an hour." Oh. He felt his soul drop to the pit of his- nonexistent stomach. "ah, uh. alright. i'll try to be less ribiculous by then."  
She chuckled. "You better be, I'll have to fight you if you're more of a numbskull!!"

"aw, tibia me is a hard thing." He responded emptily. He'd heard that before.  
And made it before. What was the point of this? He never heard or saw anything new from them. Only you. It was another reason he was head over calcaneus for you.  
The captain gave another hearty chuckle. "Alright, I gotta get going. Seeya, Sans."

"bye." He waved quietly, feeling tired already. Being so obsessed was tiring. Nothing else felt like this and it annoyed him, but he was willing to put up with it all for them. You.  
Waiting wasn't hard. He was always really patient, but it was hard to wait for you sometimes. All he wanted was to just see your face, that'd be enough for a rough day. A smile sent his way would disable anything from bringing him out of the clouds, their silver lining being whatever you were made of. Determination? He didn't give two cares.

Even Papyrus noticed Sans' ever-growing affections. The taller brother was the only one allowed to hug him for so long- but Sans allowed the human to hug him, and at one point when they thought nobody else was looking, kissed Sans' cheekbone.  
It's hard to hide romance from The Great Papyrus. But not like Sans cared,  
he only cared about you right now. Even his brother was starting to take the lower priority; which at first, was something he tried to let not happen. He wanted you two to be equally cared for, but..  
Some things just don't work out that way.

His mind drifted to when you first were 'touchy' with him, as the taller skeleton had put it.  
It had happened yesterday, but it felt like minutes had passed. He remembered it so well- down to every detail. What you were wearing. Any little imperfections on your face.. It was so sweet. He thought you were so adorable- and even then, you attracted him in another way. A slightly more.. obvious one.

He thought- for lack of better words, excuse my french- you were fucking attractive. It was a mindless haze of lust and love that pooled in his mind, dripping and bubbling with his confused jumbled emotions for you.  
Thinking back to the 'touchy' moment soothed him, with their vivd warmth.  
You were sitting next to him at Grillby's with Papyrus. It was warm; but you were still cold, and snuggled up against the small skeleton. He was soft, and lovely.. Good and comforting..

_You two were exchanging jokes, and of course, the taller brother was cringing and looking embarrassed to be near such awful 'comedians', but had a pity smile decoring his features._  
The smaller gave a light hum. This was what gave fuel to his obsession, awakened him to what it truly was.  
Your gentle eyes settled upon the fries in front of you, beginning to quietly eat as Sans joined in. His fries were drenched in ketchup; drowning and wishing to be free of liquid tomato death, but were not going to be anytime soon. 

_"so," He shifted his gaze towards them, his face empty of anything that wasn't his usual grin._  
"So." They responded back, giving Papyrus one glance. He was on his phone, more then likely talking to Undyne.  
A mischevious expression settled across their cute face, and they gave Sans a light peck on the cheek bone. They had already noticed how he eyes them occasionally, and turns away as soon as they look at him, his face turning slightly blue.  
"wh- kid, what was that for?" He asked, as he tried to keep his face from turning any deeper of a color. "Mm? What was what for?" You asked, feigning ignorance in every word as you plucked one fry from his loose phalanges, despite the fact he'd just been about to eat it.  
The taller of the two had seen it out of the corner of his eye- but didn't say anything. He'd tease Sans later.  
And so he did. A lot. 

It was out of slight envy, admittably. He also found the human slightly attractive, but not nearly as much as Sans. He found them cute and their personality nice, someone he would date perhaps. The little kiss was something the younger was a tad jealous of, wishing someone would give him one as well, but he always pushed it aside, ignoring his feelings.  
The small skeleton was torn from his thoughts upon noticing the one who stood in front of him. It just so happened to be.. oh.

Speak of the devil, the tall skeleton Papyrus was here. His expression was that of someone who was not impressed- and most certainly, he was far from 'impressed'.  
Impressed. He liked that word. He never saw that expression on you. He wanted to-.. wait. His brother is here. Keep a clear mind, stop thinking of [y/n], Sans.  
Etched into his expression was a look of annoyance. He'd deal with this now and get it over with, he had more important things. For instance, you.

"BROTHER," The taller greeted, booming voice slightly swayed by the growing thorn in his emotional side. All in all, the other was growing fustrated with his older sibling. He looked down at the stocky smaller, his arms rested on the table and chin in his hand.  
Previously, he had his eyes closed with a dreamy expression settled upon his face. It was hard to want to tear him out of that, but this was an important subject. If he didn't discuss it now, there would never be a chance to.

Papyrus felt impatience over this, wanting to just tug at his scarflike cape and groan in fustration. One of his hands was positioned on his hip to keep him from doing it already.  
"uhh. sup, pap?" The older greeted, looking upwards at the tall skeleton monster. The caped monster gave a great sigh. "SANS, UM.. I WISH TO DISCUSS THE HUM-.. [y/n] WITH YOU. BEFORE THEY.. PASS BY, I M-MEAN."  
To emphasize how serious this was, he had used your real name instead of just calling you 'human'. The smaller gave a nod in silence, his lack of brows knitting together in confusion.

"YOU S-SEE.. THIS.. MIGHT BE THE LAST TIME WE SEE THEM.." The tall brother began, hands fumbling together. That was right; they were to fight Asgore soon, having said goodbye and spent time with everyone. The smaller wasn't worried, the human had made their way out of this a million times by now.  
"AND.. I WANT TO ASK THEM.. SOMETHING IMPORTANT. THEY AND I WENT ON A PLATONIC DATE AT ONE POINT, BUT.. I WANT TO ASK THEM TO.." The poor tall skeleton had no idea what he was in for. The smaller's obsession and tactics to try to yank the human's affections towards him and away from anyone else was borderline desperation,

and it would be a long time before he'd let anyone get near them in such a way on his watch. Quietly drumming his fingers against the flat surface of the guard sentry station, the older awaited what his younger, taller sibling had to say.  
"OUT TO.. SOMETHING.. LESS PLATONIC? MAYBE MORE.. UM.. R-ROMANTIC? NOT ANYTHING BAD, OF COURSE!! I JUST.. NYEH, I WANTED YOUR APPROVAL. I WASN'T SURE HOW TO GO ABOUT IT. I WAS JUST ORIGINALLY GOING TO ASK THEM IF THEY WANTED TO SHARE SOME SPAGHETTI, BUT.. IT FEELS LIKE I S-SHOULD DO MORE THEN THAT." The innocent brother admitted sheepishly, quietly rubbing the back of his own skull.

"BUT.. I ALSO LIKE SOMEONE ELSE? AND H-.. THEY'RE A MONSTER LIKE ME, BUT.. I DON'T KNOW." He sighed, sitting quietly in front of the brother he hoped would give helpful advice, but received something slightly different.  
"not sure bro. i'm no expert in love." The older gave a heavy sigh, rubbing his forehead for a moment, before Papyrus spoke again.  
"AND, UM.. I KNOW YOU LIKE THEM, AND THEY LIKE YOU, BUT.." Now, he was interrupted.

"bro. just go for what you want. i don't mind either way. chill." The older skelebro responded in a simple tone. He wouldn't have to worry about all of this once you were finally here! But this couldn't wait, now could it? He could never just push his brother off to the side- maybe sometimes, but not now.  
"ARE.. YOU SURE? I MEAN. IF THIS ISN'T A PROBLEM TO YOU!" The younger continued to hesitate and pause. It was mostly his feelings he was unsure of from the sounds of it; the older would just have to convince him out of it.

That was easier said then done, but he knew he could do it. A strange feeling twisted in that weak, heart-shaped source of life of his, feeling like a red, powerful source of more life.  
Determination. That was the word. When had he ever felt determined? He wasn't sure, but it sure as hell was welcomed. It definitely wasn't the kind that everyone else was used to, it having settled in their being long ago, but more of an emotion.

He never really had any of that 'determination' stuff. Too intimidating and unhealthy-for-monsters for his tastes.  
With a gentle wave of his hand, the unstable older gave a warm, about-as-real-as-my-social-life smile. His causal, laid-back words gave the other a definite amount of relief, despite how sad they'd happen to be. But, he'd pull through and cheer himself up. It was just his thing.

"alright, if you really want my opinion.. bro, you already know i dont like mtt, but i can't say that you'd be better off without em'.. give tin-can a try." The 'wiser' already knew; there was no point in hiding it. Why bother? He had better things to do.  
This was his brother, though. Even if he did not approve of the walking, talking tin can and his mischevious winks, hip sways and flashy boots- he only wanted him happy.

Not the robot. He couldn't give two shits about the robot.  
"W-WAIT, YOU KNEW?? WHY HADN'T YOU JUST SAID SO, BROTHER?!" A small hint of disbelief was twisted into the orange-tinted younger, his face flushed out of embarrassment. He lightly tugged on the orange-red fabric softly wrapped around his neck to hide his shock, but it failed tremendously.

"eh." With a casual shrug, the smaller gave a wink, dark bags under his eyesockets becoming all the more clear. The taller already knew; it was not a thing the other would dare speak about. "well, pal-ange, s' no real secret. i-" He was interrupted by his brother's stern tone.  
"BROTHER, IF YOU MAKE ANOTHER PUN I AM LEAVING. RIGHT NOW". His words were certainly a double-bladed sword there- if he did speak in puns once more, his "twisted" (yeah, sure) ways of comedy would drive him away and he'd be alone with his thoughts of you, but on the other hand, this was his brother. He enjoyed time with him.

.. But he enjoyed time thinking of you.. hm. So tough. Those buds of feelings having bloomed and nowhere near begun to wither in him had struck a hard deal; his brother or his thoughts of [y/n].  
In the end, he chose a third option.  
Go with the flow.

Adjusting himself, he raised his hands in defeat. "ok, bro. i won't make another pun. you win." His posture was lazy, however relaxed. His mind was setting together careful puzzle pieces; how to just nudge Papyrus in the right direction.  
"YOU BETTER! NYEHEHEH, THIS IS A GLORIOUS REVELATION!! NO MORE PUNS!!" Papyrus 'celebrated', his joyous tone somewhat of an exaggeration. He secretly enjoyed his brother's puns of course, it was always that idea of 'i'm too cool for that'.

"hey, i never said 'no more'. i only said i won't make another right now." The one clad in blue gave a wink, wondering when this would be over and he could just sleep. God, it felt like it'd been too long since he'd last slept.  
Giving a heavy sigh, the orange younger was a little annoyed. ".. BROTHER, CAN I ASK ONE THING OF YOU?" His voice was gentle, despite how he felt.

"sure." The older responded, his own words bland and simple.  
"COULD.. YOU NOT CALL HIM A TIN CAN???" "no can do." "SANS!! PLEASE, HE TRIES."  
They argued back and forth over it for a bit, Papyrus eventually relenting to his brother's rude nickname. There was no changing Sans' mind when he was set on something.

Eventually, the younger left, giving his goodbyes to the older. His messy, crimson thoughts were gathered together once more; slurred at the thought of this particular human he obsessed over.  
He felt that dangerous thin ice he had to trek on to gain your affections would be worth it- eliminate specific monsters from his life (and yours), do whatever he had to, it didn't matter to him at all.  
Sure, it wouldn't be easy to fit the pieces together and blind you to what he was really doing, but he would pull it off. He was the manubrium, after all.

Okay, that one was bad. To shrug off his bad pun that embarrassed him because he was talking to himself,  
he sent a glance towards his watch with a small, awkward cough. About half an hour to go- not too bad, he'd have time to prepare. He laid his arms down on the grainy wood, and closed his eyesockets.  
You'd be here soon. You'd be here soon. You'd be here soon.

The thought kept him awake, dancing mockingly in his skull and burning the thought of his lust towards you in his lit eyesockets. He felt so tired- exhausted- but he just couldn't sleep. His soul pounded like a drum,  
giving him a headache. He was so excited. The short skeleton had never really felt like this before, and it was exhilirating, liberating even.

He opened his eyes, continuing to await your presence.

It had taken you a little longer than expected to arrive, but here you were, shoes clicking on the burning ground below.  
You walked closer, your [h/c] hair swaying slightly as you moved. The skeleton sitting there was laid back slightly in the usual relaxed position, eyes closed and a faint snore whistling from his nasal septum. How? You weren't sure, but you didn't really mind either.

You gently tapped on the sentry post, feeling the aged, heated wood under your fingertips. The surface was rough, and the noise was enough to awake him.  
"mm? oh, sup [y/n]." He greeted with a lax voice, one eye open and grin slightly stretching. You gave him an innocent smile, making his soul soar. He wanted to just reach out and gently run his phalanges through your hair.

"Hello there, Sans. How are you?" You inquired gently as you sat on the wood, catching his gaze as it trailed down to your legs for a moment. "m'alright." He responded in a slightly dreamy tone.  
"You sound kind of out of it." You pointed out with a small smile, patiently waiting as he shrugged. "nah. just a li'l tired. actually did my job."  
The human gave a giggle, their smile making his cheekbones turn slightly blue. It was hardly noticable, but it was still something.

"so uh. got a question for you." He took on a surprisingly serious tone as he sat up in a more proper manner, his jacket being slightly tugged down to regain himself a bit better.  
"Shoot." You responded casually, trusting the skeleton not to ask anything bizarre- but he caught you off guard. He always did.  
"so. we've known eachother for a while, and i'm not gonna sugarcoat it."

"you're really nice." He looked down for a moment, hesitating. He began to slightly stumble over his words, losing what little confidence he had before- and you were just quietly listening, not interrupting. This was embarrassing, but he knew you wouldn't care. You two were friends.  
"and- um. well. i-- uh. kind of wanted.. to.. be more then friends." He forced the words out, closing his eyesockets due to being flustered.

He felt the silence that ensued would go on forever- but you gave a small chuckle, leaned forward and gently placed your hand under his chin, gently pulling him closer-  
and kissed him on the nose.  
He had exactly what he wanted, and he hadn't even done anything brutal yet.

_Yet._

**Author's Note:**

> i hope i did this right lmao  
> uh this is my first fanfic on ao3 so if i got somethin wrong please tell me  
> i wrote it v early in the morning because i was Bored, and because a friend dared me to  
> i normally don't like writing this kinda stuff but it was fun to test out my writing skills on this one, i tried really hard  
> edit;; holy shit thats a lot of kudos and hits. thanks guys i didnt expect this


End file.
